Per @joatca on #4, specs are failing on master.

Possibly an intermittent failure? I can't reproduce, but possibly it will reproduce on CI.

By the way, your final test "sequence number" always fails on my system. The first two pings seem to both come back with sequence number 0.

Hi,

I get the following when I try to run the example in the readme. I'm using crystal 0.32.1 on Ubuntu Server 16.04 LTS.

Unhandled exception: Arithmetic overflow (OverflowError)
from lib/icmp/src/icmp/packet.cr:0:16 in 'calculate_checksum'
from lib/icmp/src/icmp/request.cr:29:19 in 'initialize'
from lib/icmp/src/icmp/request.cr:14:5 in 'new'
from lib/icmp/src/icmp.cr:54:9 in '__crystal_main'
from /usr/share/crystal/src/crystal/main.cr:97:5 in 'main_user_code'
from /usr/share/crystal/src/crystal/main.cr:86:7 in 'main'
from /usr/share/crystal/src/crystal/main.cr:106:3 in 'main'
from __libc_start_main
from _start
from ???

Thanks,
-G

Nice library! Was worried I'd have to code ping myself. :-)

I can't get it to work on Linux unless I'm root, even though I think I have /proc/sys/net/ipv4/ping_group_range set correctly. Any idea what might be wrong?

$ cat /proc/sys/net/ipv4/ping_group_range 
0	2147483647
$ uname -r
4.15.3-2-ARCH
$ id
uid=1000(fraser) gid=1000(fraser) groups=1000(fraser),10(wheel),14(uucp),100(users),614(adbusers)
$ crystal run test.cr 
failed to create socket:: Operation not permitted (Errno)
  from /usr/lib/crystal/socket.cr:0:5 in 'initialize'
  from /usr/lib/crystal/socket.cr:69:3 in 'initialize'
  from IPSocket
  from lib/icmp/src/icmp.cr:44:9 in 'initialize'
  from lib/icmp/src/icmp.cr:26:5 in 'new'
  from test.cr:16:14 in '__crystal_main'
  from /usr/lib/crystal/crystal/main.cr:11:3 in '_crystal_main'
  from /usr/lib/crystal/crystal/main.cr:112:5 in 'main_user_code'
  from /usr/lib/crystal/crystal/main.cr:101:7 in 'main'
  from /usr/lib/crystal/crystal/main.cr:135:3 in 'main'
  from __libc_start_main
  from _start
  from ???
$ sudo crystal run test.cr 
0 valid_response took 2ms
1 valid_response took 1ms
2 valid_response took 1ms

The code is just your example modified with a local IP address (although 8.8.8.8 obviously doesn't work either):

require "icmp"

statistics = ICMP::Ping.new("192.168.0.5").ping(count: 3) do |request|
  puts "#{request.sequence} #{request.status} took #{request.roundtrip_time}ms"
end
p statistics

Cool library, I enjoy using it.

When sending request on dead (aka, ping failed) address, the command just hangs.

https://github.com/robacarp/icmp.cr/blob/master/src/icmp/request.cr

require "icmp"

HOST = "227.227.227.217"
ICMP::Ping.new(HOST).ping.["success"]
ICMP::Ping.new(HOST).ping(count:1)["success"]

Yielding it does not fix the issue.

Cheers